A Note on Reason
(see lecture # 1, 2, 12)

The distinction between reason (or the rational) and rationalism is crucial.

Rationalism affirms
(i)  reason has access to ultimate reality
(ii)  ultimate reality is what is naturally intelligible
(iii)  reason is the essence of humankind
(iv)  reason is unimpaired, or at least so slightly impaired as to be naturally correctable

The Christian faith affirms

(i)  faith (i.e., a predicate of grace) has access to ultimate reality (There’s no natural access to ultimate reality.)
(ii)  ultimate reality is Spirit or the effectual presence of Jesus Christ
See Balth.: “…the word of God is not of this world and hence can never be discovered in the categories and accepted patterns of human reason.” 61  “I was appointed by God from all eternity to be the recipient of this…eternal word of love, a word, which, pure grace though it be, is…more rational than my reason, with the result that this act of obedience in faith is in truth the most reasonable of acts.” 62 
(iii)  spirit (i.e., our having been created for relationship with God as the good) is the essence of humankind reason as a source of knowledge of God, of the kingdom of God, of the highest wisdom, has been devastated.
Note the naturalistic criticisms of reason:  
Freud
Marx
     Foucault
     postmodernists generally.

Note the theological criticisms of reason:

Paul (“…they became futile in their thinking and their senseless minds were darkened. Claiming to be wise, they became fools….” Rom 1:21-22)
(“…the futility of their minds; they are darkened in their understanding, alienated from the life of God because of the ignorance that is in them…..” Eph. 4:18) (Reason is impaired with respect to our life in God [knowledge of God]. This is not to say that reason has become irrational. (This would be a logical contradiction.) Irrationality is the obliteration of reason, not the corruption of reason. There is still an earthly wisdom and an earthly good of which fallen humankind is capable and which we ought not to disdain.)

Jeremiah (“…how long shall your evil thoughts lodge within you?” Jer. 4:14. “The heart is deceitful above all things and desperately corrupt. Who can understand it?” Jer. 17:9)

How much of the rational is rationalisation? The rationality of rationalisation is perfectly rational; it just happens to serve an unconscious end and provide the legitimisation of that end. In the same way the rationality of psychosis is rational.

Reason still functions adequately, e.g., with respect to mathematics. But as soon as reason is deployed in the service of a natural end beyond the relations of logic, the distortion of reason is evident.

The Christian faith affirms that grace alone (faith) frees reason from reason’s captivity and restores reason’s integrity. For this reason the command of God to love him with our minds is not impossible. Not to love God with our minds is both disobedience and idolatry. Faith is not a species of irrationality. Isaac Watts wrote a textbook on logic that was used for 40 years at Oxford, Cambridge, Harvard and Yale. Wesley too wrote a text on logic. That which mathematics and science probes is the naturally intelligible.

Pascal: “Reason is never more reasonable than when it acknowledges the limits to reason.”